Coulomb excitation of Na-29,Na-30: Mapping the borders of the island of inversion

Publication Type
Journal Article
Year of Publication
Seidlitz, M.
Reiter, P.
Altenkirch, R.
Bastin, B.
Bauer, C.
Blazhev, A.
Bree, N.
Bruyneel, B.
Butler, P. A.
Cederkall, J.
Davinson, T.
De Witte, H.
DiJulio, D. D.
Diriken, J.
Gaffney, L. P.
Geibel, K.
Georgiev, G.
Gernhauser, R.
Huyse, M.
Kesteloot, N.
Krucken, R.
Lutter, R.
Pakarinen, J.
Radeck, F.
Scheck, M.
Schneiders, D.
Siebeck, B.
Sotty, C.
Steinbach, T.
Taprogge, J.
Van Duppen, P.
de Walle, J. V.
Voulot, D.
Warr, N.
Wenander, F.
Wimmer, K.
Woods, P. J.
Wrzosek-Lipska, K.
Name of Publication
Physical Review C
Date Published
Short Title
Coulomb excitation of Na-29,Na-30: Mapping the borders of the island of inversion
Accession Number
ISBN Number

Nuclear shell evolution in neutron-rich Na nuclei around N = 20 was studied by determining reduced transition probabilities, i.e., B(E2) and B(M1) values, in order to map the border of the island of inversion. To this end Coulomb-excitation experiments, employing radioactive Na-29,Na-30 beams with a final beam energy of 2.85 MeV/nucleon, were performed at REX-ISOLDE, CERN. De-excitation gamma rays were detected by the MINIBALL gamma-ray spectrometer in coincidence with scattered particles in a segmented Si detector. Transition probabilities to excited states were deduced. The measured B(E2) values agree well with shell-model predictions, supporting the idea that in the Na isotopic chain the ground-state wave function contains significant intruder admixture already at N = 18, with N = 19 having an almost pure two-particle-two-hole deformed ground-state configuration.